Reinforced concrete cribbing



April 1, 1958 T. D. WILSON REINFORCED CONCRETE CRIBBING Filed Sept. 26,1955 5 Sheets-Sheet 1 ,INVENTOR 'THERON D. WILSON BY ana M.

ATTORNEY April 1, 1958 T. D. WILSON 2,823,613

REINFORCED CONCRETE CRIBBING Filed Sept. 26, 1955 5Sheets-Sheet 2 FIG.4

INVENTOR THERON 1) WILSON TTORNEY April 1, 1958 T. D. WILSON 2,828,613

REINFORCED CONCRETE CRIBBING Filed Sept. 26, 1955 5 Sheets-Sheet 3 l NVEN TOR THERON 1). WILSON BY GHfi L ATTORNEY April 1, 1958 T. D. WILSON2,828,613

REINFORCED CONCRETE CRIBBING Filed Sept. 26, 1955 5 Sheets-Sheet 4 INVENTOR THEEON 1). WILSON,

BY 6M4.

ATTORNEY April 1, 1958 T. D. WILSON 2,828,613

REINFORCED CONCRETE CRIBBING Filed Sept. 26, 1955 5 Sheets-Sheet 5 FIG.7

INVENTOR THERON D. WILSON ATTORNEY United States Patent F REINFORCEDCONCRETE CRIBBING Theron D. Wilson, Knoxville, Tenn. ApplicationSeptember 26, 1955, Serial No. 536,621

2 Claims. (CI. 61-47) Because of their comparatively low cost, it iscommonplace today to employ prefabricated concrete units for theconstruction of crib retaining walls and the like as a substitute forthe more expensive gravity or cantilever type Wall. Since crib retainingwalls, regardless of how they are formed, are subjected to the sameforces, their stability against overturning and sliding has heretoforebeen secured by anchoring the front members, or stretchers, in variousways. been successfully used in the continuous back wall anchorage typeconstructed in the form of rectangular cells in which the back wall istied to the front Wall by headers, the members being articulated bymeans of concrete lugs. Another such crib is the fish tail anchoragetype in which the fish tail anchorages overlap to-support the anchorends of the headers and in which the stretchers are pinned to the freeends of the headers. Still another type employs a single unit more orless in the form of a closed V, wherein the legs of the unit-extend backinto the fill. Such arrangements are described in the April, 1944,bulletin of the Portland Cement Association (Structural Bureau) entitledConcrete Information, designated No. ST 46, commencing on page 1thereof.

Although these and other similar cribbing arrangements have been foundvery useful, yet they possess cerr tain disadvantages, the mostimportant of which are their comparative inflexibility because of thedifferent shapes of the units or elements employed, such as distinctiveheaders, stretchers and fillers, and the relative high costs of theirfabrication and installation.

Accordingly, an object of my invention is toprovid an article ofmanufacture consisting of a-standard,-specially shaped, preformed,reinforced concrete element adapted to be used both as a header andstretcher in the construction of a retaining Wall or as the principalbuilding unit in the erection of piers, silos, pools, storage bins,

formed, reinforced, moulded parts which can be erected in the minimumamount of time by unskilled labor.

Another object of my invention is to provide a concrete retaining wallconsisting of similar preformed interlocked elements which is inherentlystable and at the same time is of sufficient yieldability forself-adjustment without disruption or injury to itself.

A further object of my invention is to provide a species of cribbingconstructed of preformed, reinforced concrete elements of substantiallythe same size and shape wherein the members thereof are interlocked insuch manner that the interlocks become tighter in direct proportion tothe back pressures tending to overturn or to slide the same.

In general, the preferred form of my crib comprises the use of similarpreformed concrete units or elements laid in zig-zag fashion with theirends overlapped and interlocked together to form a wall although, aswill later appear, such units or elements may also be used to formseveral different types of structures.

For example, one such crib which has 2,828,613 Patented Apr. 1, 1 958'ice- The precise nature of my invention will be best understood byreference to the accompanying drawings forming a part of thisspecification, in which like reference numerals have been used todesignate corresponding parts, and in which- Fig. 1 is a frontelevational view of one form of my cribbing element;

Fig. 2 is a top plan view of the same;

Fig. 3 is a front elevational view of another form of my cribbing unitsimilar to Fig. 1 except the vertical dimension of the middle portionthereof is smaller;

Fig. 4 is a perspective view of the preferred form of my cribbing; I

Fig. 5 is another form of cribbing employing the unit illustrated byFig. 1;

Fig. 6 is another form of cribbing of the continuous back wall type ofanchorage employing the unit illustrated by Fig. 1; and

Fig. 7 is a pier, pool, silo, storage bin or the like employing one formof my unit.

In' the particular exemplification of my invention illustrated by Figs.1 and 2, it will be seen that I have provided a prefabricated,reinforced concrete unit or element 1 moulded into a predeterminedlength and substantially rectangular in cross-section at itsmid-section. Two channels, 3 and 4, are moulded in both the top andbottom sides of the ends of the unit to. provide heads or lugs 2, thechannels intersecting at such angles as to provide on each side of theunit upstandingand depending enlargements 5 and 6 having V-shapedsidewalls or shoulders constituting channel boundaries. These heads orlugs are of the same vertical dimension as the vertical dimension of themain or body portion 1 ofthe unit where a closed face type of cribbingisdesired.

As previously stated, the unit illustrated by Fig. 3 is the same in allrespects as that illustrated by Fig. 1 exside wall of the unit nextabove it, thus providing positive locking action against movement of thestructure in both horizontal and longitudinal directions. The reason forthisis that the zig-zag arrangement inetfect provides isoscelestriangles, which may be reversed, whereby horizontal pressures on thestructuredue .to the earth fill behind it are directed upon the legs ofthe triangles, tending to brace one leg against the other. Due to thefact that the legs at the corners of the construction are interlocked inthe manner stated, the greater the back pressure exerted upon such legsby the back fill, the tighter the interlocks will become. This will betrue regardless of whether the unit illustrated by Fig. 1, whichprovides a closed face type of wall, or the unit illustrated by Fig. 3,which provides an open face type of structure, is utilized.

Manifestly, the wall illustrated by Fig. 4 can function as a foundationfor many kinds of superstructures be cause the webs of each member bearsupon the web of the member next below it along its full length.Consequently, the weight of the superstructure is transmitted throughsolid concrete to the foundation.

Regardless of whether the unit illustrated by Fig. l or Fig. 3 isemployed, it can be made lighter and, therefore, cheaper by formingvertically extending channel slots 7 therein.

The apertures in the heads of the units are provided because, whereconditions seem to indicate the necessity of positively anchoring anystructure made up of such units, anchoring rods in the form of iron bars9 may be inerted through the aligned holes and driven into the ground,as illustrated by Fig. 4.

Referring to Fig. 5, it will be seen that a continuous straight openface type of wall is provided by superimposing one row of units onanother, the units in each row. being in spaced alignment, and byoverlapping the adjacent ends of the units in'each row with the middleportion of the units in the row next above it. In this form, the rows ofthe units constituting the wall proper function as spacers. achieved byusing other similar units as headers. 'For this purpose one end of eachheader is extended at an angle as the wall is built up through the slotsor channels in the overlapped ends of the spacers in such manner thatthe anchor ends of adjacent headers will overlap and interlock with eachother. By this arrangement anchorage is obtained by surrounding aportion of the filling material by pairs of interlocked legs that extendback into the fill, and articulation is by means of the concrete headsor lugs on the ends of the units.

A wall of the continuous back wall type anchorage is constructed in theform of square cells, as illustrated by Fig. 6. As a matter ofprocedure, this type of wall is constructed precisely as is the wallillustrated by Fig. 5 except the headers are extended rearwardly atright angles to the spacers and the back wall is built up andinterlocked with the rear ends of the headers in the same manner as isthe front wall. The ends of the headers project through the front faceof both walls. Sliding of one header on another is prevented by theconcrete lugs.

By the foregoing arrangements it will be seen that curved walls may bebuilt due to the flexibility of the units. But regardless of which typeof wall is adopted, backfilling should be done so as not to produceheavy impact against the crib and to produce practically uniformpressure on the units.

Another use of my unit is in the construction of a pier, pool, silo,storage bin or the like. In fact, my unit may have police or militaryapplications as in the construction of a pill box or road block asillustrated by Fig. 7.

By this figure it will be seen that a multisided structure is formed bypositioning the units in hexagonal formation with their adjacent endsoverlapped and interlocked, the units on each side of the hexagon beingsuperimposed upon ach other. If the structure is to be used as a silo,it becomes necessary to cement up the cracks and provide a roof over thesame.

Having thus fully described my invention what I claim as new and desireto secure by Letters Patent of the United States is:

1. As a subcombination in a cribbing structure, a plurality of similarelongated concrete units generally rec- Anchorage of the spacers is=tangular in cross-section and having top, bottom and side walls, eachof said units having channels in the top "and bottom walls at the endsthereof, the channels on the same side of each end intersecting eachother and extending obliquely from the lateral sides of the unit formingpairs of opposed shoulders each having plane converging sidesconstituting a V-shaped configuration, the end portion of one unit beingsuperimposed at an angle upon the end portion of another unit with oneside of each of the opposed pair of ll-shaped shoulders on that endportion abutting throughout their lengths the lateral side walls of theother unit whereby the units are interlocked at their abutting ends andare capable of being positioned at a reverse angle with respect to eachother and remain so interlocked.

2. A cribbing comprising, in combination, a plurality of stacks ofsimilar elongated concrete units, each unit being generally rectangularin cross-section and having top, bottom and side walls and each unithaving channels in the top and bottom walls at the ends thereof, thechannels on the same side of each 'end of said units intersecting eachother and extending obliquely from the lateral side walls of the unitforming pairs of opposed shoulders, each shoulder having planeconverging sides constituting a V-shaped configuration, the ends of theunits in one stack being superimposed at an angle upon the end portionsof the units in the next adjacent stack with one side of each of thepair of opposed V-shaped shoulders on a bottom unit abutting throughouttheir lengths the lateral side walls of the unit superimposed thereonwhereby a zig-zag structure is formed and wherein the units areinterlocked at their abutting ends and are capable of being positionedat a reverse angle with respect to each other and remain so interlocked.

OTHER REFERENCES Precision Block, Precision Building System, Inc., 8,1950.

May

